<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Cache
 * @subpackage Zend_Cache_Frontend
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Output.php 16541 2009-07-07 06:59:03Z bkarwin $
 */


/**
 * @see Zend_Cache_Core
 */
require_once 'Zend/Cache/Core.php';


/**
 * @package    Zend_Cache
 * @subpackage Zend_Cache_Frontend
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Cache_Frontend_Output extends Zend_Cache_Core
{

	private $_idStack = array();

	/**
	 * Constructor
	 *
	 * @param  array $options Associative array of options
	 * @return void
	 */
	public function __construct(array $options = array())
	{
		parent::__construct($options);
		$this->_idStack = array();
	}

	/**
	 * Start the cache
	 *
	 * @param  string  $id                     Cache id
	 * @param  boolean $doNotTestCacheValidity If set to true, the cache validity won't be tested
	 * @param  boolean $echoData               If set to true, datas are sent to the browser if the cache is hit (simpy returned else)
	 * @return mixed True if the cache is hit (false else) with $echoData=true (default) ; string else (datas)
	 */
	public function start($id, $doNotTestCacheValidity = false, $echoData = true)
	{
		$data = $this->load($id, $doNotTestCacheValidity);
		if ($data !== false) {
			if ( $echoData ) {
				echo($data);
				return true;
			} else {
				return $data;
			}
		}
		ob_start();
		ob_implicit_flush(false);
		$this->_idStack[] = $id;
		return false;
	}

	/**
	 * Stop the cache
	 *
	 * @param  array   $tags             Tags array
	 * @param  int     $specificLifetime If != false, set a specific lifetime for this cache record (null => infinite lifetime)
	 * @param  string  $forcedDatas      If not null, force written datas with this
	 * @param  boolean $echoData         If set to true, datas are sent to the browser
	 * @param  int     $priority         integer between 0 (very low priority) and 10 (maximum priority) used by some particular backends
	 * @return void
	 */
	public function end($tags = array(), $specificLifetime = false, $forcedDatas = null, $echoData = true, $priority = 8)
	{
		if ($forcedDatas === null) {
			$data = ob_get_contents();
			ob_end_clean();
		} else {
			$data =& $forcedDatas;
		}
		$id = array_pop($this->_idStack);
		if ($id === null) {
			Zend_Cache::throwException('use of end() without a start()');
		}
		$this->save($data, $id, $tags, $specificLifetime, $priority);
		if ($echoData) {
			echo($data);
		}
	}

}
